I think your interpretation of “if I don’t live in a simulation, then a fraction x of all humans lives in a simulation” as P(SIM or A) is wrong
Huh?
The paper talks about P(SIM | ¬SIM → A), which is equal to P(SIM | SIM ∨ A) because ¬SIM → A is logically equivalent to SIM ∨ A. I wrote the P(SIM | ¬SIM → A) from the paper in words as P(I live in a simulation | if I don’t live in a simulation, then a fraction x of all humans lives in a simulation) and stated explicitly that the if-then was a logical implication. I didn’t talk about P(SIM or A) anywhere.
Huh?
The paper talks about P(SIM | ¬SIM → A), which is equal to P(SIM | SIM ∨ A) because ¬SIM → A is logically equivalent to SIM ∨ A. I wrote the P(SIM | ¬SIM → A) from the paper in words as P(I live in a simulation | if I don’t live in a simulation, then a fraction x of all humans lives in a simulation) and stated explicitly that the if-then was a logical implication. I didn’t talk about P(SIM or A) anywhere.